Comp and Trial run

Comp noun - Something given to someone without expectation of a return.

Trial run and comp are semantically related in examination topic. In some cases you can use "Trial run" instead a noun "Comp".

Trial run noun - Trying something to find out about it.

Comp and trial run are semantically related in check topic. Sometimes you can use "Comp" instead a noun phrase "Trial run", if it concerns topics such as standard.